The O Mint mark of the New Orleans Mint intended to have been struck on 1892-O Barber dimes and quarter dollars was inadvertently punched into a single Barber half dollar reverse die.

The result is the much coveted 1892-O Barber, Micro O half dollar.

An example graded Mint State 63 by Professional Coin Grading Service is being offered in Heritage Auctions’ June 23 sale of selections from the Eugene H. Gardner Collection of U.S. Coins.

The sale, to be held at the Ukrainian Institute of America at the Fletcher-Sinclair Mansion, 2 E. 79th St., in New York City, comprises 646 lots.

For more information, visit the Heritage Auctions website.